TM 5-3805-258-24-1S Y S T E M S O P E R A T I O NPOWER TRAIND I F F E R E N T I A LSShims (23) are used to make an adjustment to thetooth contact (wear pattern) between pinion (24)and ring gear (17).Rings (3 and 20) are used to make an adjustmentto the free movement (backlash) between pinion (24)and ring gear (17). Rings (3 and 20) are also used tomake an adjustment to the bearing preload of bear-ings (2 and 21).The inside components of the differential get theirlubrication from oil thrown around inside the differ-ential. Flat surfaces on spider (14) let oil go to bear-ings (15). The supply for lubrication oil is a reservoirin the axle housing.OPERATIONStraight FORWARD or REVERSEWhen the machine moves in a straight directionwith the same amount of traction under each drivewheel, the same amount of torque on each axle holdsthe pinions so they do not turn on the spider.Pinion (24) turns ring gear (17). Ring gear (17)turns cases (1 and 18). Cases (1 and 18) turn spider(14). Spider (14) turns side gears (4 and 19) throughpinions (13). Pinions (13) do not turn on the spider.The side gears turn the axle shafts. The same amountof torque is sent to each wheel.This gives the same effect as if both drive wheelswere on one axle shaft.FORWARD or REVERSE TurnWhen the machine is in a turn, the inside wheel hasmore resistance to turn than the outside wheel. Thisresistance causes different torques on the oppositesides of the differential. It is easier for the outsidewheel to turn than it is for the inside wheel. Theoutside wheel starts to turn faster than the insidewheel.Pinion (24) turns ring gear (17). Ring gear (17)turns cases (1 and 18). Cases (1 and 18) turn spider(14). Spider (14) turns side gears (4 and 19) throughpinions (13). Since it takes more force to turn oneside gear than it does the other, pinions (13) turnaround the spider. As the pinions turn, they movearound the side gears. This lets the outside wheelturn faster than the inside wheel.The same amount of torque is sent to both theinside and outside wheels. This torque is only equal tothe amount needed to turn the outside wheel.Loss of Traction (Wheel Slippage)When one wheel has more traction than the other,the operation of the differential is the same as in aturn. The same amount of torque is sent to bothwheels. This torque is only equal to the amount need-ed to turn the wheel with the least resistance.3-53